JPH10500869A - Hysteroscopy fluid delivery system - Google Patents

Abstract

An open loop system for delivering fluid during hysteroscopic surgery. The system includes first and second fluid conduits (12, 14) in fluid communication with the uterine cavity of a patient. First and second measuring devices (26, 28) are provided for measuring the amount of fluid flowing into and out of the uterus. The measuring devices (26, 28) produce electronic signals which are communicated to a controller (30) which uses them to calculate a value reflecting the difference in in-flow and out-flow. This difference is then compared with a preset value; if the preset value is exceeded, the surgeon knows the patient is absorbing too much fluid, and the procedure may be terminated.

Description

Description: FIELD OF THE INVENTION The present invention relates to the field of hysteroscopic surgery performed in conjunction with the delivery of fluid to the uterine cavity, and more particularly to a system for delivering this fluid. BACKGROUND OF THE INVENTION U.S. Pat. No. 5,242,390 discloses a method and apparatus for thermally removing the lining of the uterus (known as the endometrium). This patented device comprises a hysteroscope having a proximal portion for insertion into the uterus through the vagina and a distal grasping and visualizing portion. The hysteroscope includes both optical means for observing the uterine cavity and channel means for delivering a controllably heated liquid into the cavity for tissue coagulation, and further comprises insulating means for the hysteroscope. Prepare. This insulation means is intended to transport heated liquid and coagulate it with this fluid in order to prevent heat damage to other body tissues other than endometrial tissue (eg vaginal tissue and endometrial tissue). When doing so, it insulates other body tissues from the heat of the potentially damaging liquid. The device further comprises means for supplying fluid into and out of the uterine cavity, and control means for adjusting the temperature and pressure of the heated liquid. The method described in this patent comprises the steps of (a) direct monitoring by an endoscope having channel means for delivering and introducing fluid into the uterus at a pressure sufficient to inflate and directly expose the endometrial surface. Dilating the uterine cavity with a physiologically compatible aqueous solution (e.g., saline or other suitable liquid), and (b) confirming that the proximal portion of the hysteroscope is properly positioned within the uterine cavity. Confirmed by appropriate visualization of the structure, (c) withdrawing the aqueous solution from the uterine cavity, thus making it nearly collapsed, and (d) monitoring the endometrial tissue coagulation temperature under the hysteroscopy. The heated aqueous carbohydrate solution (or a suitable equivalent solution) is applied to the uterine cavity at a pressure sufficient to directly expose the entire endometrium and for a time sufficient to maintain contact with the entire surface of the heated solution. Sent and introduced into By expanding the uterine cavity in a state of collapsed in this way, thereby a step to produce a uniform and complete destruction of the endometrium. This patent discloses a means for supplying liquid to a hysteroscope having the form of a syringe barrel and plunger and containing a heated liquid to be manually injected into the inlet port of the hysteroscope sheath. Fluid derived from the uterine cavity and returned through the sheath channels and ports is circulated into the waste reservoir. Other syringe barrels and cold liquid supply means in the form of plungers are optionally available. Various valves are disclosed for controlling the supply and discharge of various liquids. It is further known to perform endoscopic procedures on the uterus, including circulating fluid in the uterus for visualization purposes. In order to maintain a clear view of the surgeon, the circulating fluid must be free of blood and other free tissue typically associated with such surgery. During such surgery, problems can arise if the patient absorbs large amounts of fluid into the circulation (or fallopian tubes (tubal tubes)) during the introduction of the solution. In certain hysteroscopic procedures, it is known that patients absorb large volumes of fluid (of the order of 2,000 or 3,000 cc), which can cause serious death-related complications. is there. Obviously, it is very important to precisely monitor the amount of liquid used to perform these procedures so as not to absorb too much. The fluid delivery system disclosed in U.S. Pat. No. 5,242,390 does not provide a practical way to perform such monitoring. In copending U.S. patent application Ser. No. 08 / 227,724, an invention is proposed that solves the problem of monitoring circulating fluid by providing a closed loop conduit that includes a graduated chamber through which circulating fluid passes. ing. The chamber can be monitored optically to see if the fluid level is constant, otherwise the procedure can be terminated. The system described in this pending application is particularly suitable for the delivery of fluids used to remove or sterilize the endometrium. However, closed-loop systems cannot always be used for fluid delivery for other types of hysteroscopic procedures, because the recirculating fluid is not free of blood and other free tissue that cannot be removed in a practical way. Because it is rapidly polluted. SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned disadvantages of the prior art. Accordingly, the present invention provides an open loop system for a delivery fluid used to perform a transendoscopic procedure involving the uterine cavity, which allows for precise monitoring of the volume of fluid in use at all times. is there. In its broadest aspect, the present invention comprises first and second fluid conduits for delivering and withdrawing first and second flows of a physiologically compatible fluid into and out of a patient's uterine cavity, respectively. Prepare. The system measures the magnitude of the first and second streams ("magnitude" means flow velocity, pressure, volume, weight, or other measurable property that reflects the amount of fluid introduced). And means for sending first and second signals indicating this. The system further includes a controller for receiving the first and second signals and measuring a value indicating whether a second flow magnitude is different from the first flow magnitude. The first is when the measured difference exceeds a preset value, e.g., when the amount of fluid flowing out of the uterus is less than the inflow, and the difference exceeds a selected value, and thus when the patient absorbs excess fluid. Means are provided for terminating the flow. This value depends on the type of action taken. The system further includes means for heating the first stream of fluid. In one preferred embodiment, the device is an open loop conduit system for circulating liquid. The system includes a first fluid conduit for introducing a first flow of a physiologically compatible fluid into a uterine cavity of a patient, and a second conduit for directing a second flow of the fluid from the uterine cavity. Is provided. The system further includes means for measuring the magnitude of the first flow and generating a first electrical signal indicative thereof, and measuring the magnitude of the second flow and indicative of the second electrical signal indicative thereof. Generating means. A controller receives the first and second signals and uses the magnitude indicated to indicate whether the second flow differs by more than a predetermined value from the first flow and thereby indicate to the patient Calculate a value that indicates the fluid that has been absorbed. In another embodiment of the system of the present invention, the term "magnitude" is defined as the weight of the fluid. The system further includes a source of a physiologically compatible fluid of known weight, the fluid source in fluid communication with the first conduit for supplying the uterus. A reservoir is placed in fluid communication with the second conduit and contains fluid derived from the uterine cavity. The first and second measuring devices are formed as electronic gravimetric measuring devices (strain gauges, piezoelectric modules, etc.) and generate signals proportional to the respective weights of the fluid source and the reservoir. This signal is sent to the controller, which sums the two weights and compares the sum with the known initial weight of the fluid source. If the total weight differs from the preset value, the initial weight, the surgeon will know that the patient is absorbing too much fluid and will stop the procedure. Preferably, the fluid source is positioned above the patient's height and does not require any pressure or pumping other than gravity to flow into the uterus. The reservoir may be positioned below the patient and provided with a pump that pumps fluid from the uterine cavity in operative association with the second conduit and the reservoir to assist in withdrawing fluid from the uterus. Such a gravity-based delivery system has significant advantages over prior art systems that actually pump fluid into the uterine cavity (e.g., "Spring balance: simple monitoring of excess fluid during hysteroscopy"). System, Lancet, 343, April 2, 1994, pages 834-837). Prior art systems are not inherently safe because the pressure in the uterus is essentially uncontrollable. The pressure created by the arrangement of the present system is a predetermined pressure determined by how high the fluid source is located above the patient (typically 3 or 4 feet (about 90 cm or 120 cm)). Does not exceed the maximum value of. By placing a pump, which may be a suction pump or a peristaltic pump, downstream of the uterine cavity, the fluid is more easily withdrawn and the safety factors are increased because the pressure in the uterus is reduced when fluid is withdrawn. In contrast, pumps located upstream of the uterus increase uterine pressure to pump. If such a pump fails, uterine pressure can rise to the point of injury or rupture. If the downstream pump of the present invention fails, the pressure in the uterus will simply drop and have no adverse effects. As another safety measure, the system further comprises a valve disposed in the first conduit and communicating with the receiving means. The valve opens and closes to allow or block fluid flow from the fluid source to the uterus. Further, the controller operates to close the valve when the weight difference between the fluid source and the reservoir exceeds the initial weight of the fluid source by more than a preset value. In another aspect of the present invention, the size is defined as a volume or a flow rate, and the measuring means comprises a first and a second flow rate measuring device such as a flow meter operably provided in the first and the second flows. A second device. The signals from these devices are provided to a controller that calculates a value representing the difference between the first and second flow measurements. The controller then compares these differences with the current value. Thus, if, for example, the flow rate into the uterus exceeds the flow rate out of the uterus by more than a preset value, the surgeon can know that the patient has absorbed too much fluid and stop the procedure. This embodiment, like the previous embodiment, is also located in the first conduit and automatically stops fluid flow into the uterus when the difference between the two flow rates exceeds a preset value. Equipped with a valve. BRIEF DESCRIPTION OF THE FIGURES The following description is best understood with reference to the figures. FIG. 1 is a schematic view of a hysteroscope sheath provided with an entrance port and an exit port used for performing endoscopic surgery on the uterus, and FIG. 2 is a hysteroscope sheath of FIG. FIG. 3 is a schematic diagram of an open loop of the system of the present invention for supplying liquid to the system; FIG. 3 shows another configuration of a fluid source useful in the present invention. Throughout the description the following detailed description of preferred embodiments, to indicate the same members of the present invention shown in multiple figures, the same reference numerals are used. Referring to FIG. 1, an endoscope sheath 7 suitable for endoscopic procedures of the uterus is described. Such procedures often require the continuous introduction of large volumes of fluid into the uterine cavity to enlarge the uterus and obtain a clear field of view. Fluid from the uterine cavity UC returns through the hysteroscopic sheath 7 (the fluid flow channels are not shown; see US Pat. No. 5,242,390 for details) and exits the sheath 7 via the outlet port 9. . Of course, the circulation system of the present invention can be used with other types of hysteroscopes and uterine cannulas as well. FIG. 2 shows a schematic form of the endoscope sheath 7 and the like used for the patient P. An endoscopic procedure is being performed on this patient. The present invention includes an apparatus 10 for circulating a physiologically compatible fluid. In FIG. 2, arrows indicate the direction of fluid flow through the various elements of the system 10. The system 10 includes a first conduit 12 that directs a physiologically compatible fluid into the uterine cavity UC via an inlet port 8. The system further includes a second conduit 14 for withdrawing fluid from the uterine cavity UC via the outlet port 9. A physiologically compatible fluid source 16 is provided in fluid communication with the first conduit 12. The physiologically compatible fluid source 16 is positioned several feet (tens of centimeters) higher than the patient P so that the fluid flows into the uterine cavity UC with a pressure head formed only by gravity. preferable. A fluid reservoir 18 is in communication with the second conduit 14 to receive fluid derived from the uterine cavity UC. This reservoir 18 is located lower than the patient and preferably assists the fluid flow derived from the uterine cavity UC by a pump 22 arranged along the second conduit 14. A valve 20 is disposed within the first conduit 12 and, when opened and closed, allows the flow of fluid from the fluid source 16 to be started or stopped. The valve 20 is connected to a controller 30 which is further connected to a pair of measuring means 26, 28 in the form of an electronic balance. Scale 26 weighs the fluid in fluid source 16 and scale 28 weighs the fluid in reservoir 18. These scales 26, 28 generate first and second signals indicating the weight of the fluid source 16 and the reservoir 18, respectively. These first and second signals are sent to the controller 30. If desired, a heater 24 can be positioned within conduit 12 to heat the liquid during a given procedure. The operation of the tenth embodiment of the system of the present invention is as follows. At the start of the procedure, the fluid volume in fluid source 16 is measured by scale 26 and this value is stored in controller 30. The valve 20 is then opened, allowing fluid to flow into the uterine cavity UC. The fluid widens the uterine cavity and allows the operator to get a good view of its interior. After the uterine cavity has been dilated, fluid continues to flow in and excess fluid is drawn through the second conduit 14 with the aid of the pump 22. Excess fluid subsequently flows into the reservoir 18. The weight of the fluid in the reservoir 18 is continuously measured by the scale 28, and the amount of the fluid in the reservoir 16 is similarly measured. The weight of each of the fluid source 16 and the reservoir 18 is summed by the controller and compared to the initial weight of the fluid stored therein. In addition, the controller 30 stores a preset value representing a difference predicted in consideration of the nature of the operation and the amount of unmeasurable fluid (in the uterine cavity, in the sheath, etc.). This preset difference will vary from procedure to procedure, ie, if the fluid is not heated, the patient can safely absorb a much larger volume of fluid than if it were a heated liquid. Then, the controller compares the difference between the weight of the fluid in the fluid source 16 and the reservoir 18 and the weight of the initial fluid with a preset value. If the preset value is exceeded, a signal is sent to the controller valve 20 to stop fluid flow. Alternatively, the initial weight of the fluid source may be determined after the system has been filled with fluid, ie, after the fluid has flowed into and out of the uterus. In this case, the total weight of the fluid in the fluid source and the reservoir is approximately equal to the initial weight of the fluid source when the procedure is being performed. Then, the preset value stored in the controller is smaller because it is not necessary to consider non-meterable liquids in the system. Of course, it can be understood that the measuring means 26 and 28 may be other than an electronic balance, and may be a means for measuring a value other than the weight of the fluid. For example, an apparatus for measuring a flow rate or a flow velocity flowing through the first and second conduits may be used. Devices such as flow meters send a signal to the controller indicating the amount of fluid flowing through the conduit. In this case, the controller has a different program from that of the above-described embodiment. Instead of summing the values sent by the measuring means 26, 28, the controller measures the difference between them and compares this difference to a preset value stored internally. That is, if the flow rate or flow rate in the second conduit is much less than the flow rate or flow rate in the first conduit, the surgeon will know that the patient is absorbing too much fluid. The controller 30 then sends a signal to the valve 20 to close the valve and stop fluid flow into the uterine cavity. FIG. 3 shows another arrangement of a physiologically compatible fluid source used in the device of the present invention. In this case, two fluid sources 16 are provided and hooked side by side. Many hysteroscopic procedures require the introduction of a large volume of fluid into the uterine cavity, and the one in one fluid bag or bottle is easily contained. In the device shown in FIG. 3, each fluid source 16 is provided with a respective valve 32, so that it can be supplied from the other as soon as it is empty. The fluid circulation system of the present invention can be used to deliver cold or heated fluid into the uterine cavity as needed for a particular operation. Since it is not a closed loop system, a transparent and clean fluid can be continuously fed, and further, it can be continuously monitored to ensure patient safety. Furthermore, this system is more secure than prior art systems because it does not use a pump upstream of the uterine cavity. Further, since the system is based on electronic technology, continuous monitoring is possible. The system of the present invention has been described with reference to specific embodiments and examples. As will be apparent, those skilled in the art can make other variations from the present disclosure without departing from the scope of the invention. For example, while the system has been described with reference to devices for measuring weight, volume and flow, other types of measuring devices for measuring other measurable physical parameters, such as, for example, fluid pressure, may be used. It is possible. Therefore, the present invention is not limited to the above embodiments and specific examples, but is defined by the appended claims and all reasonable equivalents.

[Procedure of Amendment] Article 184-7, Paragraph 1 of the Patent Act [Submission date] July 11, 1995 [Correction contents]                                The scope of the claims 1. Flow for use in transendoscopic procedures requiring delivery of fluid to the uterine cavity of a patient A body delivery system,     A first method of gravity introducing a first flow of a physiologically compatible fluid into a uterine cavity of a patient. Tubes and     A second conduit for gravity-directing a second flow of the fluid from the uterine cavity;     Measuring and indicating a first amount of the first stream of fluid flowing into the uterine cavity; Measuring means for generating a first electrical signal;     Measuring a second amount of fluid in the second stream flowing from the uterine cavity and indicating this; Measuring means for generating a second electrical signal;     Receiving the first and second signals and determining the first and second signals based on the first and second quantities indicated thereby; The maximum flow from which the second flow can be safely absorbed by the patient. Indicates whether the values differ by a value greater than the preset value indicating the A controller that calculates a value indicative of the fluid absorbed by the patient. M 2. The calculated value is the difference between the first and second quantities and the receiver The step further acts to compare this difference to said preset value. The system according to paragraph. 3. The magnitude is defined as a flow rate, and the measuring means is configured to be a first and a second, respectively. 3. The system according to claim 2, further comprising a flow meter strain gauge provided for the two-fluid flow. Stem. 4. 3. The system according to claim 2, wherein said size is defined as a volume. 5. A source of a physiologically compatible fluid having a known initial volume and in fluid communication with the first conduit; Wherein the calculated value is the sum of the first and second quantities, The controller further measures a difference between the sum and a known initial amount of the fluid source. , Operable to compare this difference to a preset value. On-board system. 6. The size is defined as a weight, and the measuring means measures the first and second electrons. The system of claim 5, wherein 7. 2. The method of claim 1, further comprising: means for heating said first stream of liquid. System. 8. A pump provided in the second conduit, wherein the second flow of liquid 2. The system according to claim 1, wherein the pumping is performed from a palace. 9. A valve for opening and closing the first conduit, the valve connected to the controller; A switch for opening and closing the valve when the set value exceeds the preset value. 9. The system of claim 8, comprising a system. Ten. Flow for use in hysteroscopic procedures that require delivery of fluid to the patient's uterine cavity A body delivery system,     Positioned higher than the patient whose initial weight is known and undergoing endoscopic procedures An isolated physiologically compatible liquid source;     First means for continuously measuring the weight of liquid remaining in the liquid source;     A non-pressurized, physiologically compatible liquid in fluid communication with the liquid source is injected into the uterine cavity of the patient. A first conduit leading to     A second conduit for draining a physiologically compatible liquid from the uterine cavity;     Displaced lower than the patient and out of the uterine cavity in fluid communication with the second conduit A fluid reservoir containing the isolated physiologically compatible liquid;     Second means for continuously measuring the weight of the liquid in the reservoir;     The second conduit is operably provided to pump a physiologically compatible liquid from the uterine cavity. Pump to     It is connected to the first and second measuring means and measures the sum of its weights. A controller that compares the meter with a known initial weight of the fluid source and calculates the difference therebetween A system comprising: 11． The controller has a preset that represents the maximum allowable amount that the patient can safely absorb. Claim 10 further operable to compare the cut value with the difference. The described system. 12． A valve for opening and closing the first conduit, the valve being connected to the controller; The electronic means closes the valve when the difference exceeds the preset value. The system according to claim 11, operable to manipulate the system. 13. Means for stopping the flow of the first flow when the difference exceeds a preset value. The system of claim 5, further comprising a step.

────────────────────────────────────────────────── ─── Continuation of front page    (81) Designated countries EP (AT, BE, CH, DE, DK, ES, FR, GB, GR, IE, IT, LU, M C, NL, PT, SE), AU, CA, JP, KR, M X, RU

Claims (1)

[Claims] 1. Fluid delivery for use in endoscopic procedures requiring delivery of fluid to the uterine cavity of a patient Out system,     A first conduit for introducing a first flow of a physiologically compatible fluid into the uterine cavity of the patient;     A second conduit for directing a second flow of the fluid from the uterine cavity;     Measuring the magnitude of the first flow and generating a first electrical signal indicative thereof; Means,     Measuring the magnitude of the second flow and generating a second electrical signal indicative thereof; Means,     Receiving the first and second signals and, based on the magnitude indicated thereby, Indicating whether the second flow is greater than the preset value from the first flow, A controller that calculates a value indicative of the absorption of the fluid by the patient. Stem. 2. The calculated value is the difference between the first and second magnitudes, and The means is further operative to compare this difference with said preset value. The system of claim 1. 3. The magnitude is limited as a flow rate, and the measuring means is configured to be a first and a second, respectively. 3. The system according to claim 2, further comprising a flow meter strain gauge provided for the two-fluid flow. Stem. 4. 3. The system according to claim 2, wherein said size is defined as a volume. 5. A source of a physiologically compatible fluid of known size and in fluid communication with the first conduit; Wherein the calculated value is the sum of the first and second magnitudes, The controller further measures a difference between the sum and a known size of the fluid source. And wherein the difference is operable to compare to the preset value. The system according to paragraph. 6. The size is limited as a weight, and the measuring means is configured to measure the first and second electrons. The system of claim 5, wherein 7. 2. The method of claim 1, further comprising: means for heating said first stream of liquid. System. 8. Further comprising a pump provided in the second conduit, wherein the second flow of liquid is transmitted to the uterus 2. The system of claim 1, wherein the system is pumped through a cavity. 9. A valve for opening and closing the first conduit, connected to the controller, A switch that opens and closes the valve when the value exceeds the preset value. 9. The system according to claim 8, comprising: Ten. Flow for use in hysteroscopic procedures that require delivery of fluid to the patient's uterine cavity A body delivery system,     Physiology positioned higher than the patient of known weight and undergoing endoscopic procedures A compatible liquid source;     A fluid in fluid communication with the fluid source for directing a physiologically compatible fluid into the uterine cavity of the patient. One conduit,     A second conduit for withdrawing a physiologically compatible fluid from the uterine cavity;     Lower than the patient and exits the uterine cavity in fluid communication with the second conduit A fluid reservoir containing an isolated physiologically compatible liquid;     A physiologically compatible fluid is operably provided in said second conduit and from the uterine cavity. A pump for pumping,     Connected to the fluid source and the reservoir, measuring the sum, and summing the sum to the flow A controller that compares the known weight of the body source and calculates the difference therebetween. Tem. 11． The controller is further operable to compare the difference to a preset value The system according to claim 10, wherein 12． A valve for opening and closing the first conduit, the valve being connected to the controller; Wherein said electronic means closes said valve when said difference exceeds said preset value. The system of claim 11, operable to: 13. Fluid delivery for use in hysteroscopic procedures requiring delivery of fluid to the patient's uterine cavity Out system,     Introducing a first stream of a physiologically compatible fluid of known size into the uterine cavity of the patient A first conduit,     A second conduit for directing a second flow of the fluid from the uterine cavity;     Measuring the magnitude of the second flow of the fluid and measuring the magnitude of the second flow with the magnitude of the second flow; Means for measuring a difference from a known magnitude of the stream of one;     When the difference exceeds a preset value, a method of stopping the flow of the first flow is performed. A system comprising steps.